1. Field of Invention
Exemplary aspects of the present invention relate to a projector to project an image by using a liquid crystal display panel and other display elements.
2. Description of Related Art
A related art projector is assembled having a display element constructed by a discrete pixel, and an optical device of a structure laminating plural wobbling elements, each constructed by an optically transparent birefringent medium and an optically transparent phase modulating optical element of a switch type constructed by a ferroelectric liquid crystal, etc. See Japanese Patent Application No. 7-36054.
In such a projector, the polarizing direction of light passing through the birefringent optical element is alternately switched in the perpendicular direction by switching the operation of the phase modulating optical element within one frame. Thus, an optical path of the light emitted via the phase modulating optical element and the birefringent medium is switched within one frame and the clearance of a pixel can be buried. Accordingly, an image of the display element constructed by the discrete pixel can be projected as a continuous screen having no joint.
However, in the above projector, since the phase modulating optical element is switched and operated during one frame period, no stable operation of the phase modulating optical element can be easily secured, and the phase modulating optical element and its driving circuit become expensive. Otherwise, the obtained image tends to be unstable.
Further, in the above projector, no reduction in transmittance of a certain extent or more can be avoided and no generation of transmittance irregularities can be also avoided. Accordingly, a reduction in brightness of the projecting image and brightness irregularities are inevitably caused.